1. Field of the Invention
This invention relates to wireless communication systems, such as those including adaptive point to multipoint wireless communication.
2. Related Art
Wireless communication between a sender and a receiver includes sending information using a wireless communication link, in which the sender modulates information onto a wireless communication channel (such as a frequency band reserved for wireless communication between the sender and the receiver), and the receiver demodulates that information from the wireless communication channel, so as to recover the original information. The wireless communication link includes multiple physical characteristics, including characteristics of the sender's equipment and the receiver's equipment, characteristics of objects on or near communication pathways between the sender and the receiver, and characteristics of other communications overlapping communication between the sender and the receiver.
One problem with known systems is that multiple physical characteristics of the communication link between the sender and receiver can change substantially over relatively short time durations (for example, the distance between the sender and receiver or the equipment used by the sender or receiver). This is particularly so for characteristics related to interference, such as co-channel interference (CCI), and for multipath and multipoint effects, such as refraction or reflection resulting in intrasymbol interference and intersymbol interference. Moreover, these multiple physical characteristics can change independently of one another, and can have substantial and relatively unpredictable effects on one another. Selection of a set of parameters with which to optimize the communication link for one such physical characteristic can therefore be rendered less than optimal by changes in other such physical characteristics. As a result, selection of a single set of such physical characteristics can result in relatively ineffective or inefficient communication between the sender and the receiver.
Accordingly, it would be advantageous to provide a technique for adaptive point to multipoint wireless communication, in which characteristics of the communication techniques between sender and receiver can be changed adaptively in response to changes in the characteristics of the physical communication media, that is not subject to drawbacks of the known art.